DECODE_HISTOGRAM()

Overview

Returns a string of comma-separated numeric values that correspond to the probability distribution represented by a histogram of the given histogram type.

See also: Functions in 10.6 ES, in 10.6 CS, in 10.5 ES, in 10.5 CS, in 10.4 ES, in 10.4 CS, in 10.3 ES, in 10.3 CS, in 10.2 ES, and in 10.2 CS

EXAMPLES

CREATE TABLE t (
 c1 INT,
 c2 INT
);
INSERT INTO t VALUES
  (1,1), (2,2), (3,3), (4,4), (5,5), (6,6), (7,7),
  (8,8), (9,9), (10,10), (11,20), (12,30), (13,40),
  (14,50), (15,60), (16,70), (17,80), (18,90), (20,100);
SET histogram_size=10, histogram_type=SINGLE_PREC_HB;
ANALYZE TABLE t PERSISTENT FOR ALL;
+--------+---------+----------+-----------------------------------------+
| Table  | Op      | Msg_type | Msg_text                                |
+--------+---------+----------+-----------------------------------------+
| test.t | analyze | status   | Engine-independent statistics collected |
| test.t | analyze | status   | OK                                      |
+--------+---------+----------+-----------------------------------------+
SELECT hist_type, HEX(histogram), DECODE_HISTOGRAM(hist_type,histogram)
 FROM mysql.column_stats
 WHERE db_name='test' and table_name='t';
+----------------+-----------------+---------------------------------------+
| hist_type      | HEX(histogram)  | DECODE_HISTOGRAM(hist_type,histogram) |
+----------------+-----------------+---------------------------------------+
| SINGLE_PREC_HB | [HEX_DIGITS...] | 0.00000,[...]                         |
| SINGLE_PREC_HB | [HEX_DIGITS...] | 0.00000,[...]                         |
+----------------+-----------------+---------------------------------------+

CHANGE HISTORY

Release Series

History

10.6 Enterprise

  • Present starting in MariaDB Enterprise Server 10.6.4-1.

10.6 Community

  • Present starting in MariaDB Community Server 10.6.0.

10.5 Enterprise

  • Present starting in MariaDB Enterprise Server 10.5.3-1.

10.5 Community

  • Present starting in MariaDB Community Server 10.5.0.

10.4 Enterprise

  • Present starting in MariaDB Enterprise Server 10.4.6-1.

10.4 Community

  • Present starting in MariaDB Community Server 10.4.0.

10.3 Enterprise

  • Present starting in MariaDB Enterprise Server 10.3.16-1.

10.3 Community

  • Present starting in MariaDB Community Server 10.3.0.

10.2 Enterprise

  • Present starting in MariaDB Enterprise Server 10.2.25-1.

10.2 Community

  • Present starting in MariaDB Community Server 10.2.0.

EXTERNAL REFERENCES